This invention relates to bottom sand for growing aquatic plants in aquariums and aquariums for growing aquatic plants using such bottom sand.
Recently, growing plants in water contained in aquariums, sometimes with pet fish, has become popular.
In hydroponics, it is essential to circulate and filter the water in order to prevent it from becoming turbid and opaque.
Meanwhile, the sand laid at the bottom of aquariums is required to serve as a medium to support the plants. Nevertheless, there has been no technical concept to use such bottom sand in aquariums for both efficient filtering of water and efficient growing and support of aquatic plants.
The object of this invention is to provide bottom sand that permits both efficient purification of water and efficient growing and support of plants and aquariums for growing aquatic plants using such bottom sand as illustrated in FIG. 3.
To solve the problem described above, granular sinter consisting essentially of volcanic ash is added to the bottom sand. The granular sinter has such a bonding strength that granules crush when a pressure of about 2.5 kg/cm2 or less is applied to a layer of the sinter 1.0 cm thick. The aquarium according to this invention comprises a layer of bottom sand of the type described above and has a water-circulating system installed or included therein.